岩石创面“植被-土壤”系统恢复:影响因素与生态演替

Restoration of“vegetation-soil”system on rock-cut slope:Influencing factors and ecological succession process

岩石创面高陡、水分和养分难保持、植物难生长,是山体基岩在人类干扰下因上覆植被-土壤系统部分或完全丢失后,以一定倾角出露地表而成的次生环境问题,可导致景观破碎、加剧水土流失、增加自然灾害发生频率、恶化生境和威胁区域生物多样性。人工恢复时,恢复目标是快速再现岩石创面上覆植被-土壤系统,以美化环境和固坡防灾;人工植物群落可高于或类似于"原来"状态,但不能恢复原样;岩石创面上覆植被-土壤系统的演变涉及3个阶段、4类生态系统。人工恢复短期恢复效果好、效率高,恢复群落植被盖度好且具有一定生物多样性,但受成本、技术等限制,其难以普遍使用,尤其是在偏远和高寒山区。岩石创面自然恢复普遍存在,虽然其恢复速率较慢,早期植被群落盖度小、结构较差,但在人为少量辅助下,可成为偏远和高寒山区岩石创面植被-土壤系统恢复的有效途径。自然恢复和人工辅助恢复时,岩石创面植被-土壤系统的演变虽然只包含2个阶段,但仍涉及4类生态系统类型,会先恢复到类似于原生态系统的水平,再继续动态发展。岩石创面上覆植被-土壤系统的恢复深受人工恢复使用材料、重金属污染、岩石创面特征及临近生态系统等的影响。未来,不但要继续优化或开发基质,也要深化岩石创面生态恢复综合评价、微生物和自然恢复等方面的研究。

The high and steep rock cut slope,due to the partial or complete loss of the vegetation-soil system interfered by human activity,is a kind of secondary environmental issue,which caused by the bedrock exposes to the surface.The restoration objective of artificial restoration is to cover the existing rock cut slope quickly with a vegetation-soil system,to improve the environment and stabilize the slope.This artificial vegetation-soil system may be higher than or similar to“original”state of undisturbed slopes that represents the unexcavated state in mountainous regions.Under artificial restoration,the evolution of vegetation-soil system on rock cut slope generally involves three stages and four types of ecosystems.Artificial restoration on rock cut slope takes a short-term beneficial effect in vegetation coverage and certain biodiversity,however,it is difficult to be widely used,especially in the remote and high mountainous areas due to the high cost and technology limitation.In contrast,natural recovery can be regarded as a feasible way to restore the“vegetation-soil”system of rock cut slopes in the remote and high mountainous areas,assisted by human activity,though the recovery rate is slow,and the small coverage of vegetation community and poor ecological structure occur in initial recovery stage.The evolution of the vegetation-soil system under natural recovery and human-assisted restoration on rock cut slopes involves 2 stages and 4 types of ecosystems.The influencing factors associated with the restoration of vegetation-soil system on rock cut slopes include artificial restoration materials,heavy metal pollution,characteristics of rock wounds,adjacent ecosystems and so on.In future,not only the optimization or development of artificial soils need to be strengthened,but also the comprehensive evaluation of the ecological restoration and restoration of microorganism and natural recovery need to be prompted.